The present invention relates to a magnetic sensor which is used in measuring a magnetic field, and, more particularly, to a plane magnetic sensor and a plane magnetic sensor for a multidimensional magnetic field analysis which suitably measure the magnetic field over a wide area.
In order to measure the magnetic field on the periphery of an object to be measured (such as a permanent magnet and electronic equipment with a magnet embedded therein), a fluxmeter, a gauss meter and the like are conventionally used, and a sensor such as a hole element is positioned to measure a predetermined measuring point on the periphery of the object to be measured and then the position is changed manually. A magnetic flux density which is measured by the gauss meter and the like is plotted by each measuring point, whereby the magnetic field on the periphery of the object to be measured is processed to be visually recognized.
However, according to the conventional method of measuring the magnetic field as described above, it is necessary to move one sensor from a predetermined measuring point to another, which is time consuming. For this reason, it is not suitable for detecting magnetic field changes on the periphery of the object to be measured in real time. Further, when the measuring point is changed manually, the positioning to the respective measuring points is difficult. Meanwhile, in order to eliminate the aforementioned disadvantages, it is possible to arrange a plurality of sensors in the same plane and to simultaneously measure the magnetic fields over a wide area. Thereby, the magnetic fields at the respective measuring points in the same plane can be measured in a short time without moving the sensor. However, since it is necessary to connect the respective sensors to lead wires for supplying driving voltage or a driving current and to lead wires for detecting an output current or output voltage, it is not practical because of the large number of the lead wires and of its complexity.
The present invention is made to overcome the above disadvantages, and it is an object of the present invention to provide a plane magnetic sensor and a plane magnetic sensor for a multidimensional magnetic field analysis which can measure magnetic fields of a plurality of measuring points in, a very short time, has a small number of lead wires, and is suitable for the practical use.
In accordance with one aspect of the present invention, a plane magnetic sensor is provided. The plane magnetic sensor comprises a sensing layer which is composed of an arbitrary-sized plane magnetoresistance effect film, to pass a current therethrough due to a tunneling effect only when voltage reaches or exceeds a predetermined value, and to change its resistance value to show a giant magnetoresistance effect when directions of magnetization of magnetic particles change according to the strength of a magnetic field, and conductor layers which are laminated on respective surfaces of the magnetoresistance effect film and are composed of a plurality of line conductor films formed in linear shapes along directions of the respective surfaces with predetermined intervals therebetween. Further, the line conductor films of one conductor layer and the line conductor films of the other conductor layer are arranged to intersect to each other in plan view, with the magnetoresistance effect film therebetween.
In a preferred embodiment of the present invention, adjacent films of the line conductor films to compose the conductor layers are not connected to each other but are arranged independently.
In a preferred embodiment of the present invention, the magnetoresistance effect film to compose the sensing layer is a granular film made from an insulating oxide containing metal fine particles of magnetic material.
In accordance with another aspect of the present invention, a plane magnetic sensor for a multidimensional magnetic field analysis is provided. The plane magnetic sensor for the multidimensional magnetic field analysis comprises a plane magnetic sensor comprising a sensing layer composed of an arbitrary-sized plane magnetoresistance effect film, to pass a current therethrough due to a tunneling effect only when voltage reaches or exceeds a predetermined value, and to change its resistance value to show a giant magnetoresistance effect when directions of magnetization of magnetic particles change according to the strength of a magnetic field, and conductor layers which are laminated on respective surfaces of the magnetoresistance effect film and are composed of a plurality of line conductor films formed in linear shapes along directions of the respective surfaces with predetermined intervals therebetween, wherein the line conductor films of one conductor layer and the line conductor films of the other conductor layer are arranged to intersect to each other in plan view, with the magnetoresistance effect film therebetween, and at least one other plane magnetic sensor including a sensing layer which is composed of an arbitrary-sized plane magnetoresistance effect film having a magnetic anisotropy, and conductor layers which are laminated on the respective surfaces of the sensing layer and are formed by a plurality of line conductor films formed in linear shapes along directions of the respective surfaces with predetermined intervals therebetween, with the line conductor films of one conductor layer and the line conductor films of the other conductor layer being arranged to intersect to each other in plan view with the magnetoresistance effect film therebetween. Further, the plane magnetic sensors are laminated via an insulation member so that a magnetoresistance change can be detected multidirectionally.
In a preferred embodiment of the present invention, adjacent films of the line conductor films to compose the conductor layers are not connected to each other but are arranged independently.
In a preferred embodiment of the present invention, the magnetoresistance effect film to compose the sensing layer is a granular film made from an insulating oxide containing metal fine particles of magnetic material.
In accordance with still another aspect of the present invention, a plane magnetic sensor is provided. The plane magnetic sensor comprises a plurality of sensing layers which are composed of arbitrary-sized plane magnetoresistance effect films, to pass a current therethrough due to a tunneling effect only when voltage reaches or exceeds a predetermined value, and to change its resistance value to show a giant magnetoresistance effect when directions of magnetization of magnetic particles change according to the strength of a magnetic field, and a plurality of conductor layers which are, laminated between magnetoresistance effect films to compose the sensing layers and on outer surfaces of the magnetoresistance effect films to compose the sensing layers arranged outside, and are composed of a plurality of line conductor films formed in linear shapes along directions of respective surfaces with predetermined intervals therebetween. Further, the line conductor films to compose the conductor layers are arranged to intersect to each other in plan view, with the magnetoresistance effect film therebetween.
In a preferred embodiment of the present invention, the adjacent films of the line conductor films to compose a pair of the conductor layers arranged outside are not connected to each other but are arranged independently, and adjacent films of the line conductor films to compose a pair of the conductor layers arranged inside are connected to each other and are arranged integrally, and intersections of the line conductor films to compose the pair of the conductor layers arranged outside and intersections of the line conductor films to compose the pair of the conductor layers arranged inside are formed to almost correspond to each other when viewed in plan.
In a preferred embodiment of the present invention, neither adjacent films of the line conductor films to compose a pair of the conductor layers arranged outside nor adjacent films of the line conductor films to compose a pair of the conductor layers arranged inside are connected to each other but are arranged independently, and intersections of the line conductor films to compose the pair of the conductor layers arranged outside and intersections of the line conductor films to compose the pair of the conductor layers arranged inside are formed to almost correspond to each other when viewed in plan.
In a preferred embodiment of the present invention, the pair of the conductor layers arranged outside are connected to a driving circuit for supplying driving voltage or a driving current, and the pair of the conductor layers arranged inside are connected to a detecting circuit for detecting output voltage or an output current.
In a preferred embodiment of the present invention, the magnetoresistance effect film to compose the sensing layer is a granular film made from an insulating oxide containing metal fine particles as magnetic material.
In accordance with yet another aspect of the present invention, a plane magnetic sensor for a multidimensional magnetic field analysis is provided. The plane magnetic sensor for the multidimensional magnetic field analysis comprises a plane magnetic sensor comprising a plurality of sensing layers composed of arbitrary-sized plane magnetoresistance effect films, to pass a current therethrough due to a tunneling effect only when voltage reaches or exceeds a predetermined value, and to change its resistance value to show a giant magnetoresistance effect when directions of magnetization of magnetic particles change according to the strength of a magnetic field, and a plurality of conductor layers which are laminated between magnetoresistance effect films to compose the sensing layers and on outer surfaces of the magnetoresistance effect films to compose the sensing layers arranged outside, and are composed of a plurality of line conductor films formed in linear shapes along directions of respective surfaces with predetermined intervals therebetween, wherein the line conductor films to compose the conductor layers are arranged to intersect to each other in plan view, with the magnetoresistance effect film therebetween, and at least one other plane magnetic sensor including a sensing layer which is composed of an arbitrary-sized plane magnetoresistance effect film having a magnetic anisotropy, and conductor layers which are laminated on the respective surfaces of the sensing layer and are formed by a plurality of line conductor films formed in linear shapes along directions of the respective surfaces with predetermined intervals therebetween, with the line conductor films of one conductor layer and the line conductor films of the other conductor layer being arranged to intersect to each other in plan view with the magnetoresistance effect film therebetween. Further, the plane magnetic sensors are laminated via an insulation member so that a magnetoresistance change can be detected multidirectionally.